1. Field of Invention
The present invention relates to a Hall Effect switching circuit and apparatus using the same. More particularly, the present invention relates to a Hall Effect switching circuit adapted to both N and S magnetic polarities and apparatus and method using the same.
2. Description of Related Art
For recent years, Hall Effect switching circuits using Hall Effect sensors are widely implemented to detect position change or revolution of objects. For example, a Hall Effect switching circuit is embedded in top cover (or bottom cover) to detect the distance between the top and bottom covers such that the power supply is controlled in accordance to the detected result.
Refer to FIG. 1, a prior art Hall Effect switching circuit is shown therein. The Hall Effect switching circuit 10 comprises a Hall IC 100, amplifier 110, Schmitt trigger circuit 120 and transistor 130. Firstly, the Hall IC 100 determines output voltage levels in accordance to the magnetic flux thereon. The output voltage level is amplified by the amplifier 110 and the amplified output voltage level is determined whether or not it is bigger than a predetermined value by the Schmitt trigger circuit 120. The determined result is used for controlling whether to conduct the transistor 130.
However, this kind of Hall Effect switching circuit is designed for detecting only one magnetic polarity, either N or S. Those who want to implement the Hall Effect switching circuit suffer to select a specific magnetic field generator in order to make the whole system function correctly.